<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            padding: 0;
            margin: 0;
        }
        /* 必须要写 */
        html,body{
            width: 100%;
            height: 100%;
        }
        main{
            width: 100%;
            height: 100%;
            display: flex;
            flex-direction:column;
        }
        header,footer{
            width: 100%;
            height: 100px;
            background-color: rgb(224, 154, 62);
        }
        section{
            width: 100%;
            /* flex-grow: 1; */
            flex: 1;
            background-color: rgb(42, 224, 103);
            display: flex;
        }
        .one,.three{
            width: 200px;
            height: 100%;
            background-color: rgb(241, 21, 21);
        }
        .two{
            height: 100%;
            /* flex-grow: 1; */
            flex: 1;
            background-color: rgb(206, 32, 183);
        }
    </style>
</head>
<body>
    <main>
        <header></header>
        <section>
            <div class="one"></div>
            <div class="two"></div>
            <div class="three"></div>
        </section>
        <footer></footer>
    </main>
</body>
</html>